White spot on clown

[grumpyoldman]

I added a mated pair clowns to my tank last week. The male is fine, but the female has a white spot on her dorsal fin. The white spot seemed eat away ate the area it was attached to, but has not grown, or spread. What could this be, and should I worry? She acts ok, and has been eating daily.

 

[grumpyoldman]

It looked like a small patch of cotton. It's still there, but has not grown, moved or changed.

 

[beth]

Do you have a hospital tank?

 

[grumpyoldman]

I do.

 

[beth]

Well, if it were me, and I was sure it was "cottony" on the tail, I'd use a sterile instrument to try and snip or scrape off the "cottony" part as much as possible, then swab down the infected area with disinfected. Then do an antibiotic treatment in a hospital tank--Maracyn2 for SW fish.
That "procedure" would only be contingent on if the damaged area was strictly on a fin, and not on the fleshy part of the fish.